The ARM bit sliced AES core code uses the IV buffer to pass the final
keystream block back to the glue code if the input is not a multiple of
the block size, so that the asm code does not have to deal with anything
except 16 byte blocks. This is done under the assumption that the outgoing
IV is meaningless anyway in this case, given that chaining is no longer
possible under these circumstances.
However, as it turns out, the CCM driver does expect the IV to retain
a value that is equal to the original IV except for the counter value,
and even interprets byte zero as a length indicator, which may result
in memory corruption if the IV is overwritten with something else.
So use a separate buffer to return the final keystream block.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The GNU assembler for ARM version 2.22 or older fails to infer the
element size from the vmov instructions, and aborts the build in
the following way;
.../aes-neonbs-core.S: Assembler messages:
.../aes-neonbs-core.S:817: Error: bad type for scalar -- `vmov q1h[1],r10'
.../aes-neonbs-core.S:817: Error: bad type for scalar -- `vmov q1h[0],r9'
.../aes-neonbs-core.S:817: Error: bad type for scalar -- `vmov q1l[1],r8'
.../aes-neonbs-core.S:817: Error: bad type for scalar -- `vmov q1l[0],r7'
.../aes-neonbs-core.S:818: Error: bad type for scalar -- `vmov q2h[1],r10'
.../aes-neonbs-core.S:818: Error: bad type for scalar -- `vmov q2h[0],r9'
.../aes-neonbs-core.S:818: Error: bad type for scalar -- `vmov q2l[1],r8'
.../aes-neonbs-core.S:818: Error: bad type for scalar -- `vmov q2l[0],r7'
Fix this by setting the element size explicitly, by replacing vmov with
vmov.32.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This replaces the unwieldy generated implementation of bit-sliced AES
in CBC/CTR/XTS modes that originated in the OpenSSL project with a
new version that is heavily based on the OpenSSL implementation, but
has a number of advantages over the old version:
- it does not rely on the scalar AES cipher that also originated in the
OpenSSL project and contains redundant lookup tables and key schedule
generation routines (which we already have in crypto/aes_generic.)
- it uses the same expanded key schedule for encryption and decryption,
reducing the size of the per-key data structure by 1696 bytes
- it adds an implementation of AES in ECB mode, which can be wrapped by
other generic chaining mode implementations
- it moves the handling of corner cases that are non critical to performance
to the glue layer written in C
- it was written directly in assembler rather than generated from a Perl
script
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
